JP6119412B2 - Hybrid vehicle drive control device - Google Patents

Description

  The present invention relates to a drive control device for a hybrid vehicle in which engine power is transmitted to a wheel side via a clutch and a transmission.

  Some vehicles equipped with an engine employ an AMT (Automated Manual Transmission) that automatically controls the operation of the clutch and the transmission with an actuator (for example, a solenoid) to automatically switch the speed of the transmission. In the shift control of a system employing this AMT, for example, when a shift command is generated, the clutch is released, the gear stage of the transmission is switched, and then the clutch is engaged. At that time, the throttle opening and ignition timing of the engine are controlled while the clutch is disengaged, and the rotational speed difference between the engine side and the transmission side (the difference between the engine rotational speed and the input shaft rotational speed of the transmission) is reduced to some extent. Then, there is one that engages the clutch.

  In addition, as a technique related to shift control, for example, as described in Patent Document 1 (Japanese Patent Publication No. 2011-518725), a motor is disposed between the engine and the transmission, and between the engine and the motor. In a system in which a clutch is arranged, the motor is controlled so that the input shaft on the transmission side is rotated at a rotational speed within the operating range of the engine when the clutch is engaged, so as to prevent engine stoppage or malfunction. There is something that was made.

Special table 2011-518725 gazette

By the way, the present applicant has set the throttle opening of the engine in order to reduce the difference in rotational speed between the engine side and the transmission side when the transmission is upshifted (switching to a higher speed than the current speed). We are researching a system that lowers the engine speed by cutting the fuel in a fully closed state, but the following new issues were found in the research process. If a fuel cut is performed with the throttle opening fully closed during transmission upshifting, the air / fuel ratio may vary depending on the operating conditions when fuel injection is resumed by increasing the throttle opening after the completion of the shifting operation. There is a possibility that the amount of emission (HC and NO _x ) emission increases greatly.

  Accordingly, an object of the present invention is to provide a drive control apparatus for a hybrid vehicle that can reduce the emission emission amount during upshifting of the transmission.

In order to solve the above-mentioned problems, an invention according to claim 1 is directed to an engine (11) mounted as a power source of a vehicle and a motor generator (12) connected so as to be able to transmit power, and the power of the engine (11) is In a drive control device for a hybrid vehicle, which is transmitted to a wheel side via a clutch (16) and a transmission (13), and the gear stage of the transmission (13) is switched while the clutch (16) is disengaged. During the upshift of (13), the motor (12) is driven by the power of the engine (11) while the fuel injection of the engine (11) is continued, and the motor generator (12) generates power, thereby generating the engine (11 ) comprising a control means for executing engine rotation reduction control for reducing the rotational speed (19), the control means (19), the engine when the engine rotation reduction control ( 1) The throttle opening of the engine (11) is decreased within a range where the throttle opening is not fully closed, and the throttle opening corresponding to the lower limit of the required fuel injection amount is reduced when the throttle opening is decreased. The degree is set as a lower limit guard value, and the throttle opening is limited so as not to fall below the lower limit guard value .

In this configuration, when the transmission is upshifted, the engine rotation reduction control is performed such that the motor generator is driven by the power of the engine while the fuel injection of the engine is continued and the motor generator generates electric power to reduce the rotation speed of the engine. Execute. In this way, during the upshift, the engine load torque can be increased by the power generation of the motor generator to decrease the engine rotation speed. In addition, since fuel injection is not continued and fuel cut is not performed, disturbance of the air-fuel ratio can be suppressed, emission (HC and NO _x ) emissions can be reduced, and a driver due to disturbance of the air-fuel ratio can be reduced. It is possible to prevent the deterioration of the performance.

The engine speed can also be reduced by a decrease in engine output torque due to a decrease in throttle opening (a decrease in fuel injection amount). Furthermore , when the upshift is performed, the effect of lowering the engine speed is reduced by simply reducing the throttle opening and reducing the fuel injection amount, compared to a system that performs fuel cut with the throttle opening fully closed. However, in this embodiment, the engine rotational speed can be quickly reduced by the effects of both the increase in the engine load torque due to the power generation of the motor generator and the decrease in the engine output torque due to the decrease in the throttle opening.

FIG. 1 is a diagram showing a schematic configuration of a drive control system for a hybrid vehicle in one embodiment of the present invention. FIG. 2 is a flowchart showing the flow of processing of the shift control routine during upshifting. FIG. 3 is a time chart showing an example of execution of shift control during upshifting.

Hereinafter, an embodiment embodying a mode for carrying out the present invention will be described.
First, a schematic configuration of a drive control system for a hybrid vehicle will be described with reference to FIG.
An engine 11 that is an internal combustion engine and an MG 12 (motor generator) are mounted as power sources for the vehicle. The power of the output shaft (crankshaft) of the engine 11 is transmitted to the transmission 13 via the MG 12, and the power of the output shaft of the transmission 13 is transmitted to the wheels 15 via the differential gear mechanism (not shown), the axle 14, and the like. Is transmitted to.

  A clutch 16 for interrupting power transmission is provided between the MG 12 and the transmission 13, and the clutch 16 and the transmission 13 constitute an AMT 17 (automated manual transmission). The AMT 17 automatically controls the speed of the transmission 13 by controlling the operation of the clutch 16 and the operation of the transmission 13 (shift operation and selection operation) by an electromagnetic drive type or hydraulic drive type actuator (not shown). It is supposed to switch to.

  Further, a second clutch 18 is provided between the engine 11 and the MG 12 for interrupting power transmission. Note that the second clutch 18 may be omitted, and the engine 11 and the MG 12 may be connected to each other so that power can always be transmitted.

  The hybrid ECU 19 is a computer that comprehensively controls the entire vehicle and reads output signals from various sensors and switches such as an accelerator sensor, a shift switch, a brake switch, a vehicle speed sensor (not shown) and the like. Detect the operating state. The hybrid ECU 19 transmits and receives control signals and data signals to and from the engine ECU 20 that controls the operation of the engine 11 and the transmission ECU 21 that controls the AMT 17 (such as the clutch 16 and the transmission 13). The MG 12 is controlled, and the engine 11 and the AMT 17 are controlled by the ECUs 20 and 21.

  At this time, an output signal of a sensor (not shown) that detects information related to the AMT 17 (for example, the position of the clutch 16, the shift position and the select position of the transmission 13, etc.) is input to the transmission ECU 21. An output signal of a sensor (not shown) that detects information related to the engine 11 (for example, the rotational speed of the engine 11, throttle opening, etc.) is input to the engine ECU 21, and information related to the MG 12 (for example, the rotational speed of the MG 12, etc.) The output signal of a sensor (not shown) for detecting) is input to the hybrid ECU 19.

  In this embodiment, the hybrid ECU 19 executes a shift control routine during upshift shown in FIG. 2, which will be described later, so that an upshift command (a shift command to a shift stage on the higher speed side than the present) is generated. After the clutch 16 is disengaged and the gear position of the transmission 13 is switched, the shift control for engaging the clutch 16 is executed.

When the transmission 13 is upshifted (switching to a higher speed than the current speed), the throttle opening (throttle valve opening) is set to reduce the difference in rotational speed between the engine and the transmission. In a system that reduces the engine speed by performing fuel cut with fully closed, when the throttle opening is increased and fuel injection is restarted after the completion of gear shifting operation, depending on the operating conditions, the air-fuel ratio is greatly disturbed and emissions are reduced. There is a possibility that the emission amount of (HC and NO _x ) may increase (see the broken line in FIG. 3).

  Therefore, in the present embodiment, when the transmission 13 is upshifted, the engine rotation speed is lowered by driving the MG 12 with the power of the engine 11 while the fuel injection of the engine 11 is continued and generating electricity with the MG 12. Execute drop control. Thereby, the load torque of the engine 11 can be increased by the power generation of the MG 12, and the engine rotation speed can be decreased.

  Further, in the present embodiment, the required fuel injection amount of the engine 11 is reduced by reducing the throttle opening of the engine 11 in a range where it is not fully closed during the engine rotation reduction control. As a result, the engine speed can also be lowered by a decrease in the output torque of the engine 11 due to a decrease in the throttle opening (a decrease in the fuel injection amount).

In the following, the processing contents of the shift control routine at the time of upshift of FIG. 2 executed by the hybrid ECU 19 in this embodiment will be described.
The shift control routine at the time of upshift shown in FIG. 2 is repeatedly executed at a predetermined cycle during the power-on period of the hybrid ECU 19, and serves as a control means in the claims. When this routine is started, first, at step 101, it is determined whether or not an upshift command has been generated. If it is determined in step 101 that no upshift command has been issued, the routine is terminated without executing the processing in step 102 and subsequent steps.

  On the other hand, if it is determined in step 101 that an upshift command has been generated, the process proceeds to step 102 where the clutch 16 is released. In this case, the actuator of the clutch 16 is controlled so that the clutch 16 is released.

  Thereafter, the routine proceeds to step 103, where the rotational speed of the MG 12 is set so that the engine rotational speed Ne matches the target rotational speed Ntg (= input shaft rotational speed Nin + predetermined value α) slightly higher than the input shaft rotational speed Nin of the transmission 13. MG rotation speed control for feedback control is executed. By executing this MG rotation speed control, during the period when the engine rotation speed Ne is higher than the target rotation speed Ntg, the MG 12 is driven by the power of the engine 11 while the fuel injection of the engine 11 is continued, and the MG 12 generates electric power. The engine rotation reduction control for reducing the engine rotation speed is executed.

  In the case of a system including the second clutch 18 between the engine 11 and the MG 12, the MG rotation speed control is executed with the second clutch 18 engaged. Thereby, even in the case of a system including the second clutch 18 between the engine 11 and the MG 12, the MG rotation speed control can be reliably executed.

  Thereafter, the process proceeds to step 104, and a throttle reduction operation is executed. In this case, the required fuel injection amount of the engine 11 is decreased by decreasing the throttle opening of the engine 11 within a range not to be fully closed.

  After that, the routine proceeds to step 105, where the throttle opening corresponding to the lower limit value of the required fuel injection amount (for example, the minimum injection amount that can be injected by the fuel injection valve) is set as the lower limit guard value so as not to fall below this lower limit guard value. Limit the throttle opening. Here, the lower limit guard value is set by a map or a mathematical formula according to the engine operating state (for example, engine speed). Further, retarding the ignition timing of the engine 11 is prohibited.

  After this, the routine proceeds to step 106, where it is determined whether or not the position of the clutch 16 (the degree of release of the clutch 16) has become more disengaged than the half clutch (the state in which power is transmitted while causing slippage between the input side and the output side). To do. If it is determined in step 106 that the position of the clutch 16 is not on the disengagement side with respect to the half clutch, the process returns to step 102 described above.

  Thereafter, when it is determined in step 106 that the position of the clutch 16 is closer to the release side than the half clutch, the routine proceeds to step 107 where the N shift operation of the transmission 13 is executed. In this case, the shift actuator of the transmission 13 is controlled so that the shift position of the transmission 13 is set to the N position (neutral position).

  Thereafter, the routine proceeds to step 108, where it is determined whether or not the shift position of the transmission 13 has reached the vicinity of the N position. When it is determined that the shift position of the transmission 13 has reached the vicinity of the N position, step 109 Then, the shift operation (selection and shift operation) of the transmission 13 is executed. In this case, the selection actuator and the shift actuator of the transmission 13 are controlled so that the selection position and the shift position of the transmission 13 are set to positions corresponding to the target shift stage (the shift stage after the upshift). Thereby, the gear position of the transmission 13 is switched to the target gear position.

  Thereafter, the process proceeds to step 110, and the throttle increasing operation is executed when the shifting operation of the transmission 13 is completed. In this case, the throttle opening is increased to the required throttle opening (throttle opening according to the driver's request) according to the accelerator opening or the like.

  Thereafter, the routine proceeds to step 111, where the difference (Ne−Nin) between the engine rotational speed Ne and the input shaft rotational speed Nin of the transmission 13 is within a predetermined range [predetermined value K1> (Ne−Nin)> predetermined value K2]. It is determined whether or not there is. As a result, the engine rotational speed Ne is slightly higher than the input shaft rotational speed Nin of the transmission 13, and the difference between the engine rotational speed Ne and the input shaft rotational speed Nin of the transmission 13 is small (engine rotational speed Ne and It is determined whether or not the input shaft rotation speed Nin of the transmission 13 is in a substantially identical state.

  If it is determined in step 111 that the difference (Ne−Nin) between the engine rotational speed Ne and the input shaft rotational speed Nin of the transmission 13 is outside the predetermined range, the routine proceeds to step 112, where the engine rotational speed Ne. While continuing the MG rotation speed control for feedback control of the rotation speed of the MG 12 so as to match the target rotation speed Ntg that is slightly higher than the input shaft rotation speed Nin of the transmission 13, the process returns to step 111 above.

  On the other hand, if it is determined in step 111 that the difference (Ne−Nin) between the engine rotational speed Ne and the input shaft rotational speed Nin of the transmission 13 is within the predetermined range, the routine proceeds to step 113 where the clutch 16 The engagement operation is executed. In this case, the actuator of the clutch 16 is controlled so that the clutch 16 is quickly and completely engaged.

  Thereafter, the process proceeds to step 114, where it is determined whether or not the clutch 16 is completely engaged. When it is determined that the clutch 16 is completely engaged, the process proceeds to step 115 and the MG rotation speed control is terminated. Thereafter, the routine proceeds to step 116, where the lower limit guard value of the throttle opening is canceled, and the prohibition of retarding the ignition timing is canceled.

Next, the execution example of the shift control at the time of upshift of the present embodiment will be described using the time chart of FIG.
At the time t1 when an upshift command is generated due to a shift request from the driver, the clutch 16 is released. With this clutch 16 opening operation as a trigger, the engine speed Ne is set to coincide with the target rotational speed Ntg (= input shaft rotational speed Nin + predetermined value α) slightly higher than the input shaft rotational speed Nin of the transmission 13. MG rotation speed control for feedback control of the rotation speed is executed. By executing this MG rotation speed control, during the period when the engine rotation speed Ne is higher than the target rotation speed Ntg, the MG 12 is driven by the power of the engine 11 while the fuel injection of the engine 11 is continued, and the MG 12 generates electric power. The engine rotation reduction control for reducing the engine rotation speed is executed. Thereby, the load torque of the engine 11 is increased by the power generation of the MG 12, and the engine rotation speed is decreased.

  Further, a throttle reduction operation is executed to reduce the throttle opening of the engine 11 within a range not to be fully closed, thereby reducing the required fuel injection amount of the engine 11. As a result, the engine speed is also reduced by a decrease in the output torque of the engine 11 due to a decrease in the throttle opening (a decrease in the fuel injection amount). At this time, the throttle opening corresponding to the lower limit value of the required fuel injection amount is set as the lower limit guard value, and the throttle opening is limited so as not to fall below the lower limit guard value. Further, retarding the ignition timing of the engine 11 is prohibited.

  Thereafter, at the time t2 when the position of the clutch 16 becomes the disengagement side with respect to the half clutch, the N shift operation and the shift operation (select and shift operations) of the transmission 13 are executed, and the shift stage of the transmission 13 is changed to the target shift Switch to the gear position (speed after the upshift).

  At the time t3 when the shift stage of the transmission 13 (shift operation of the transmission 13) is completed, the throttle increasing operation is executed to change the throttle opening to the required throttle opening (the driver's opening Increase the throttle opening (on demand).

  Further, if the difference (Ne−Nin) between the engine rotational speed Ne and the input shaft rotational speed Nin of the transmission 13 is within a predetermined range, the engine rotational speed Ne is slightly smaller than the input shaft rotational speed Nin of the transmission 13. It is determined that the difference between the engine rotational speed Ne and the input shaft rotational speed Nin of the transmission 13 is small (the engine rotational speed Ne and the input shaft rotational speed Nin of the transmission 13 substantially coincide). At that time, the clutch 16 is engaged.

  Thereafter, at the time t4 when the clutch 16 is completely engaged and the shift control is completed, the MG rotation speed control is terminated. Further, the lower limit guard value of the throttle opening is canceled, and the prohibition of retarding the ignition timing is canceled.

In the present embodiment described above, when the transmission 13 is upshifted, the MG 12 is driven by the power of the engine 11 while the fuel injection of the engine 11 is continued, and the engine MG 12 generates electric power to reduce the engine rotation speed. Since the rotation reduction control is executed, during the upshift, the load torque of the engine 11 can be increased by the power generation of the MG 12 to decrease the engine rotation speed. In addition, since fuel injection is not continued and fuel cut is not performed, disturbance of the air-fuel ratio can be suppressed, emission (HC and NO _x ) emissions can be reduced, and a driver due to disturbance of the air-fuel ratio can be reduced. It is possible to prevent the deterioration of the performance. Moreover, the amount of charge of a battery can be increased by generating electric power with MG12, and a fuel consumption can be improved by that much.

  Furthermore, in the present embodiment, the throttle opening of the engine 11 is decreased within the range where the engine 11 is not fully closed during the engine rotation reduction control, so that the required fuel injection amount of the engine 11 is decreased. The engine rotation speed can also be reduced by a decrease in the output torque of the engine 11 due to (a decrease in the fuel injection amount). In addition, when the upshift is performed, the effect of lowering the engine speed is reduced simply by reducing the throttle opening and reducing the fuel injection amount, compared to a system that performs fuel cut with the throttle opening fully closed. However, in this embodiment, the engine rotation speed can be quickly reduced by the effects of both the increase in the load torque of the engine 11 due to the power generation of the MG 12 and the decrease in the output torque of the engine 11 due to the decrease in the throttle opening.

  In this embodiment, when the throttle opening is decreased, the throttle opening corresponding to the lower limit value of the required fuel injection amount (for example, the minimum injection amount that can be injected by the fuel injection valve) is set as the lower limit guard value. Since the throttle opening is limited so as not to fall below the lower limit guard value, the required fuel injection amount can be prevented from falling below the lower limit value.

  Furthermore, in the present embodiment, the throttle opening is increased when the transmission operation of the transmission 13 is completed. Therefore, the throttle opening is promptly adapted to the accelerator opening after completion of the transmission operation of the transmission 13. The required throttle opening (throttle opening according to the driver's request) can be returned. In addition, by providing a lower limit guard value for the throttle opening, it is possible to speed up the return to the required throttle opening, and it is possible to approach driving as intended by the driver.

  In this embodiment, since the retard of the ignition timing of the engine 11 is prohibited when the transmission 13 is upshifted, it is possible to prevent the combustion of the engine 11 from becoming unstable due to the retard of the ignition timing. Thus, combustion efficiency can be improved, and fuel consumption can be improved.

  In the above embodiment, when the transmission 13 is upshifted, the engine speed reduction control is performed by executing the MG speed control for feedback control of the speed of the MG 12 so that the engine speed matches the target speed. (Control for reducing the engine rotation speed by driving the MG 12 with the power of the engine 11 and generating power with the MG 12) is executed, but the execution method of the engine rotation reduction control is not limited to this, for example, You may make it perform engine rotation fall control by controlling MG12 so that the electric power generation of MG12 may be made into a predetermined value, without performing MG rotational speed control.

  In the above-described embodiment, when the engine speed reduction control is performed, the MG 12 is driven by the power of the engine 11 to increase the load torque of the engine 11 to decrease the engine speed. By driving an auxiliary machine (for example, a compressor of an air conditioner) with the motive power, the load torque of the engine 11 may be further increased to decrease the engine rotation speed.

  Further, in the above embodiment, the fuel cut is not performed by providing the lower limit guard value of the throttle opening (the throttle opening is not fully closed). However, the present invention is not limited to this. The fuel cut may not be performed (the throttle opening is not fully closed) by increasing the amount or retarding the ignition timing.

  In some cases where the engine speed is low, the fuel cut may not be performed even if the throttle opening is fully closed. In such a case, the lower limit guard value of the throttle opening may be canceled. good.

  In the above embodiment, the present invention is applied to a system equipped with an AMT equipped with one clutch. However, the present invention is not limited to this. For example, a system equipped with a DCT (dual clutch transmission) equipped with two clutches. The present invention may be applied to various systems equipped with a clutch and a transmission, such as a system equipped with a clutch and MT (manual transmission).

  In addition, the present invention is not limited to the hybrid vehicle having the configuration shown in FIG. 1, and hybrid vehicles having various configurations (for example, a plurality of MGs) in which an engine mounted as a power source of the vehicle and the MG are coupled so as to be able to transmit power. The hybrid vehicle equipped with a hybrid vehicle), and a PHV vehicle (plug-in hybrid vehicle) that can be charged to a battery from a power source outside the vehicle, or an ISG (integrated MG) that combines a starter and generator It can also be applied to a starter generator type hybrid vehicle.

  DESCRIPTION OF SYMBOLS 11 ... Engine, 12 ... MG (motor generator), 13 ... Transmission, 16 ... Clutch, 17 ... AMT, 19 ... Hybrid ECU (control means), 20 ... Engine ECU, 21 ... Transmission ECU

Claims (3)

An engine (11) mounted as a power source of the vehicle and a motor generator (12) are connected so as to be able to transmit power, and the power of the engine (11) is transmitted to the wheel side via a clutch (16) and a transmission (13). And a drive control device for a hybrid vehicle in which the gear stage of the transmission (13) is switched while the clutch (16) is disengaged,
During the upshift of the transmission (13), the motor generator (12) is driven by the power of the engine (11) while fuel injection of the engine (11) is continued, and the motor generator (12) generates electric power. control means comprising a (19) that performs an engine rotation reduction control for reducing the rotational speed of the engine (11) by,
The control means (19) reduces the required fuel injection amount of the engine (11) by reducing the throttle opening of the engine (11) in a range not fully closed during the engine rotation reduction control, A throttle opening corresponding to a lower limit value of the required fuel injection amount is set as a lower limit guard value when the throttle opening is decreased, and the throttle opening is limited so as not to fall below the lower limit guard value. A hybrid vehicle drive control device. The drive control apparatus for a hybrid vehicle according to claim 1 , wherein the control means (19) increases the throttle opening when the speed change operation of the transmission (13) is completed. The drive control apparatus for a hybrid vehicle according to claim 1 or 2 , wherein the control means (19) prohibits the retard of the ignition timing of the engine (11) during the upshift.

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